Boring-tool holder.



H. E. HULL. BORING TOOL HOLDER.

APPLICATION FILEDMAR. 8, 1909.

Patented Feb. 14, 1911.

We-hm H ATTbRNEY WITNESSES UNITED orrica HORACE E. HULL, 0! LANSING, MIGHIGAN, 'ASSIGNOB 1'0 mill. V. WOW, 0%

LANSING, MICHIGAN;

nomnm'roon Roman.

- Specification of Letters Patent.

Patented Feb. 14, 1%11.

To all whom it may concern:

Be it known that 1, Homer. E. HULL, a citizen of the United States,residing at Lansing, in the county of Ingham and Stateof Michigan, haveinvented certain new and useful Improvements in Boring-Tool Holders, ofwhich the following is a specification.

My invention relates to boring tool holders. and its purpose is to makea device in which the too] shall be readily and exactly adjusted to anyrequired radius within the limits of construction, and in which at thesame time the tool shall be rigidly held in any desired position. Iattain these purposes by the mechanism shown in the accom, panyingdrawings, in which-- I Figure 1 is an elevation of my device taken fromthe side, partly in section and with part of the head broken away toshow the worm wheel; Fig. 2 is an elevation looking on a llne parallelwith the driving shaft of the lathe, or boring machine. Figs. 3, 4,

5, and 6 are views of various details of the construction, the exactpurpose of which will more fully appear further on.

ln'the drawings, 1, represents the shank of the tool holder, which is ofthe usual form, being constructed to the standard taper used in alldevices of that description, and therefore requires no particulardescription. A head, 2, is integrally formed on the outer end of thisshank, and a recess, 3, eccentrically positioned with regard to thecenter of the head, 2,-is formed in the head, 2, in which the toolholder proper, 4, is inserted so as to make a close bearing fit. A'boss, or projection, 5, is eccentrically formed on the front face of thetool holder, ,4, to furnish additional support to the tool. The toolholder, 4, is retained in its position by a screw, or bolt, 6, passingthrough its center and secured in any roper manner to the head, 2, andso arranged that the tool holder, 4, revolves around it in the recess,3, but with so close a fit as to prevent any lateral movement. Anopening, 8, eccentrically placed with regard to the center of the toolholder, 4, is made in the holder, 4, to receive the tool. This opening 8is preferably so placed that as the holder 4 revolves about its axis 6,the center of the tool mounted in said opening 8 will pass, through thecenter of revolution of the head 2. A worm wheel, 9,

is formed on the circumference 'of the screw. 10, inserted'inan opening,19, formed in the head, and revolves on bearings, 11 and 12, and isprevented from moving axially by any proper means. I at present prefer ascrew, 13, fitting a groove, 14, in the shaft ofthe worm, 10. The worm,10, is turned to any required position by any proper means, preferably amilled head, 15, and is secured in that position either by a set screw,or, as I much prefer, by a, tapered split bushing, 16, adjusted by ahexagon nut, 17, integrally formed on its outer extremity. It is evidentthat when this bushing is screwed in, it will press against the shaft,10, and will lock both the bushing 'and the screw itself, rigidly inposition.

The tool, 17 is retained in position in the holder, 4, by a similartapered bushing, but if desired, a set screw, 18, may be employed,without departing from my invention.

The operation of my device is as follows: Suppose the different parts tobe in the position shown in Fig. 2. It is evident that the tool' in theopening, 8, in the holder, will be at the mathematical center or axis ofrevolution of the boring machine, and will, therefore, be adapted tomake the beginning of the desired hole, by inserting a drill or.

other suitable tool. When this opening is completed, a boring tool isinserted in the opening, 8, the bushing, 16, is loosened and the milledhead, 15, is turned. This will cause the tool holder, 4, to revolve onthe shaft, .6, and will move the center of the boring tool along thedotted line, 20, which will cause it to recede from the center ofrevolution of the machine until the required distance for the outdesired is obtained. When this is done, the bushing, 16, is tightenedand the holder, 4, is rigidly held in position by the worm, 10, untilthe cut is completed. Under ordinary circumstances, after the bushing,16, is adjusted to a close bearing fit on the shaft, 12, it will usuallybe unnecessary to make further adjustment for a long time, as thefriction will be sufficient to hold the parts in position for anyordinary Work. It is evident that in this manner a tool can be adjusteduntil it occupies the position indicated by the dotted course, it ismanifest that by employing different sized heads, any requlred ad ust-'ment can be obtained;

recess, means projecting throu h the head and engaging directly with saitool holder for revolving the same, and a locking mem-' bcr engagingsaid last mentioned means.

2. In a boring head, a body having an v eccentrically positioned recessformed therein, a tool holder having an eccentrically ositioned openingto receive a tool formed in it, a bearing passing centrally through theholder and engaging the head whereby the holder is revolub y mounted insaid recess and means for revolving said tool holder, said meanscomprising a worm wheel and a screw.

3. A machine of the character described, a rotatable 'head' havingprojecting from wardly therefrom .and adapted for the reception of atool means for supporting the tool holder on the head comprising av boltpassin through said boss and centrally throug the holder for engagementwith the head, and which said bolt constitutes an axis or bearing forthe holder.

4. In a boring head, a body having an .eccentrically posltioned recessformed therein, a tool holder having an eccentrically positioned openingto receive a tool formed in it and revolubly mounted in said recess withmeans for revolving said tool holder,

means for lockingsaid tool holder in po-v sit-ion, substantially asdescribed.

In testimon whereof, I ailix my signature in presence 0 two witnesses.

' HORACE E. HULL.

Witnesses:

H. L. LAWRENCE, EMMA G. CAVANAGHL

